Soldiers from the Russian Pacific Fleet's flagship Varyag walk in their formation during their visit to a vessel of the Chinese People's Liberation Army (PLA) Navy in Qingdao, east China's Shandong Province, April 22, 2012. The April 22-27 Russia-China joint naval exercise, taking place in the Yellow Sea off China's east coast, involves a total of 16 vessels and two submarines from Chinese navy and four warships from Russian navy's Pacific Fleet as well as three supply ships being summoned for the exercise. [Xinhua]